Missile guidance system

ABSTRACT

1. In a system for guiding a missile to a distant target the combination comprising: A. MEANS LOCATED AT THE MISSILE LAUNCHING STATION FOR TRANSMITTING COMMAND GUIDANCE SIGNALS TO SAID MISSILE AND FOR ILLUMINATING THE TARGET WITH A RADAR SIGNAL, B. RECEIVING ANTENNA MEANS LOCATED ON THE REAR PORTION OF SAID MISSILE FOR RECEIVING SAID COMMAND GUIDANCE SIGNALS DIRECTLY FROM SAID MISSILE LAUNCHING STATION, C. SCAN ANTENNA MEANS LOCATED ON THE FORWARD PORTION OF SAID MISSILE FOR RECEIVING ECHOS OF SAID RADAR BEAM FROM SAID TARGET, D. FIRST AMPLIFIER CIRCUIT MEANS HAVING AN INPUT COUPLED TO SAID RECEIVING ANTENNA MEANS FOR AMPLIFYING SAID COMMAND SIGNALS AND HAVING AN OUTPUT, E. DETECTOR AND DECODER MEANS HAVING AN INPUT COUPLED TO THE OUTPUT OF SAID FIRST AMPLIFIER CIRCUIT MEANS FOR SUPPLYING COMMAND SIGNALS TO THE FLIGHT CONTROL SYSTEM OF SAID MISSILE, F. TRANSMITTING ANTENNA MEANS LOCATED ON THE REAR OF SAID MISSILE FOR TRANSMITTING A SIGNAL TO SAID LAUNCHING STATION, G. SECOND AMPLIFIER CIRCUIT MEANS HAVING AN OUTPUT COUPLED TO SAID TRANSMITTING ANTENNA, H. CIRCUIT MEANS COUPLING A PORTION OF THE OUTPUT OF SAID FIRST AMPLIFIER CIRCUIT MEANS TO SAID SECOND AMPLIFIER CIRCUIT MEANS FOR SUPPLYING A CARRIER SIGNAL TO SAID SECOND AMPLIFIER CIRCUIT MEANS, I. CIRCUIT MEANS COUPLING SAID SCAN ANTENNA TO SAID SECOND AMPLIFIER CIRCUIT MEANS FOR AMPLIFIER MODULATING THE CARRIER SIGNAL OF SAID SECOND AMPLIFIER CIRCUIT MEANS WHEREBY THE COMMAND SIGNALS TRANSMITTED TO SAID MISSILE MODIFIED IN ACCORDANCE WITH TARGET POSITION INFORMATION TRANSMITTED FROM SAID MISSILE.

nited States Patent Conger [451 Apr. 24, 1973 MISSILE GUIDANCE SYSTEM FOREIGN PATENTS OR APPLICATIONS 859,495 l/l96l Great Britain ..244/l4.2

Primary Examiner-Benjamin A. Borchelt Assistant ExaminerJames M. Hanley Att0rney .l. M. St. Amand, T. M. Phillips and W. O. Quesenberry EXEMPLARY CLAIM 1. In a system for guiding a missile to a distant target the combination comprising:

a. means located at the missile launching station for transmitting command guidance signals to said missile and for illuminating the target with a radar signal,

b. receiving antenna means located on the rear portion of said missile for receiving said command guidance signals directly from said missile launching station,

0. scan antenna means located on the forward portion of said missile for receiving echos of said radar beam from said target,

(I. first amplifier circuit means having an input coupled to said receiving antenna means for amplifying said command signals and having an output,

0. detector and decoder means having an input coupled to the output of said first amplifier circuit means for supplying command signals to the flight control system of said missile,

f. transmitting antenna means located on the rear of said missile for transmitting a signal to said launching station,

g. second amplifier circuit means having an output coupled to said transmitting antenna,

h. circuit means coupling a portion of the output of said first amplifier circuit means to said second amplifier circuit means for supplying a carrier signal to said second amplifier circuit means,

i. circuit means coupling said scan antenna to said second amplifier circuit means for amplifier modulating the carrier signal of said second amplifier circuit means whereb the command signals transmitted to said "11881 e modified in accordance with target position information transmitted from said missile.

2 Claims, 2 Drawing Figures 23 I8 26 PHASE SHIFTER MIXER LF. 7 l4 PHASE SHIFTER l 22 I9 TRAVELING WAVE TUBE SAWTOOTH 'AND GATE 3 4 TRAVELING WAVE TUBE l7 DETECTOR 27 AND DECODER Patented April 24, 1973 3,729,150

PQAsE SHIFTER MIXER LF.

PHASE SHIFTER I 22 l9 I TRAVELING WAVE TUBE SAWTOOTH AND GATE TRAVELING WAVE TUBE DETECTOR 7 AND --d DECODER ROBERT L. CONGER INVENTOR.

ATTORNEYS MISSILE GUIDANCE SYSTEM The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to a missile guidance system and more particularly to a missile guidance system which functions as a command guidance system with homing capabilities. Command and beam riding missile guidance systems have the disadvantages that they are not sufficiently accurate at great distances. Homing systems have sufficient accuracy, but become complicated if they are to operate in a countermeasures environment and with multiple targets present.

A missile guidance system embodying the present invention, in the initial part of the missile flight, performs solely as a command guidance system. As the missile approaches the target close enough to receive guidance information, the guidance information is relayed back to its launcher. The command guidance unit in the launcher then uses this information to correct the flight of the missile so as to intercept the target.

Accordingly an object of the present invention is to provide an improved missile guidance system which overcomes the above-mentioned disadvantages.

Another object is to provide a missile guidance system which is simple in construction but is accurate and has the ability to function properly in the presence of multiple targets and electronic countermeasures.

A further object of the invention is the provision of a relay system to relay back homing information for correcting command guidance sent to the missile.

Still another object is to provide a relay system wherein the carrier signal is transmitted to the missile and relayed back supermodulated with homing information from the target.

Still a further object is to provide a relay system wherein traveling wave tubes amplify, repeat back and modulate with homing information the transmitted carrier signal.

Other objects and many of the attendant advantages of this invention will become readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a schematic diagram illustrating the operation of the system of the present invention; and

FIG. 2 is a block diagram for the missile portion of the present system.

Referring now to the drawings there is shown in FIG. 1 a missile which has been launched from an aircraft 11 toward a target aircraft 12. Mounted on the rear of missile 10 are receiving antenna 13 and transmitting antenna 14 (see FIG. 2). Coupled to receiving antenna 13 is traveling wave tube 16 which has an output coupled to the input of detector and decoder 17, as an input to mixer 18, and as an input to traveling wave tube 19. Mounted in the front portion of missile 10 are scan antennas 21, 22 which are controlled by ferrite phase shifters 23, 24 respectively to produce a conical scan pattern (four antenna scanners are required for In operation, aircraft ll illuminates target aircraft 12 with a radar beam and also sends guidance commands to missile 10 by means of radar. During the command portion of the missile flight command signals are received by receiving antenna 13, amplified in traveling wave tube 16 and detected and decoded in device 17. Detector and decoder 17 may be a crystal diode. The decoded command signal is coupled to the autopilot (not shown) through terminal 27.

As missile 10 gets closer to target 12, the guidance information from aircraft 11 will rise above the noise level in the homing portion of the missile, i.e., missile 10 gets sufficiently close to target 12 so that radar signals reflected therefrom can be picked up by the scan antennas 21, 22. The reflected signals thus received, modulate the signal transmitted from antenna 14 to launch aircraft 1 1 to provide information which is used to correct the command signal sent to missile 10 by launch aircraft 11. The signal transmitted from aircraft 1] now serves two additional functions: it supplies a local oscillator frequency for mixer 18; and serves as a carrier for relaying back guidance and doppler information on target 12. As can be seen from the block diagram of FIG. 2, the received signal is amplified in traveling wave tube 16 and a portion of the amplified signal which functions as a carrier signal is fed to traveling wave tube 19 where it is amplitude modulated by applying the signal from scan antennas 21, 22 to its grid, thus, producing amplitude modulation of tube 19 output at the intermediate frequency. The signal at antenna 13 is the same signal received at antennas 21, 22 and contains the same variations. The signal received at antennas 21, 22, however, is delayed in time proportional to the range between missile l1 and target 12. Thus, the variations of the two received signals will match, except for the time delay. A further control signal is applied to traveling wave tube 19 from generator 28 for missile identification. The sawtooth voltage is applied to the helix of tube 19 so as to give signal sideband modulation. By this means each of the missiles fired from aircraft 11 will send back a signal with a different frequency.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a system for guiding a missile to a distant target the combination comprising:

a. means located at the missile launching station for transmitting command guidance signals to said missile and for illuminating the target with a radar signal,

. receiving antenna means located on the rear portion of said missile for receiving said command guidance signals directly from said missile launching station, 1

c. scan antenna means located on the forward por tion of said missile for receiving echos of said radar beam from said target,

. first amplifier circuit means having an input coupled to said receiving antenna means for amplifying said command signals and having an output,

e. detector and decoder means having an input coupled to the output of said first amplifier circuit means for supplying command signals to the flight control system of said missile,

f. transmitting antenna means located on the rear of said missile for transmitting a signal to said launching station,

g. second amplifier circuit means having an output coupled to said transmitting antenna,

h. circuit means coupling a portion of the output of said first amplifier circuit means to said second amplifier circuit means for supplying a carrier signal to said second amplifier circuit means,

i. circuit means coupling said scan antenna to said second amplifier circuit means for amplifier modulating the carrier signal of said second amplifier circuit means whereby the command signals transmitted to said missile modified in accordance with target position information transmitted from said missile.

2. In a system for guiding a missile to a distant target the combination comprising:

c. scan antenna means located on the forward portion of said missile for receiving echos of said radar beam from said target,

d. a first traveling wave tube amplifier having an input coupled to said receiving antenna means for amplifying said command signals and having an output,

e. detector and decoder means having an input coupled to the output of said traveling wave tube amplifier for supplying command signals to the flight control system of said missile,

f. transmitting antenna means located on the rear of said missile for transmitting a signal to said launching station,

g. second traveling wave tube amplifier means having an output coupled to said transmitting antenna,

h. circuit means coupling a portion of the output of said first traveling wave tube to said second traveling wave tube for supplying a carrier signal to said second traveling wave tube,

i. circuit means coupling said scan antennas to said second traveling wave tube for amplitude modulating the output of said second traveling wave tube whereby the command signals transmitted to said missile may be modified in accordance with target position information transmitted from said missile. 

1. In a system for guiding a missile to a distant target the combination comprising: a. means located at the missile launching station for transmitting command guidance signals to said missile and for illuminating the target with a radar signal, b. receiving antenna means located on the rear portion of said missile for receiving said command guidance signals directly from said missile launching station, c. scan antenna means located on the forward portion of said missile for receiving echos of said radar beam from said target, d. first amplifier circuit means having an input coupled to said receiving antenna means for amplifying said command signals and having an output, e. detector and decoder means having an input coupled to the output of said first amplifier circuit means for supplying command signals to the flight control system of said missile, f. transmitting antenna means located on the rear of said missile for transmitting a signal to said launching station, g. second amplifier circuit means having an output coupled to said transmitting antenna, h. circuit means coupling a portion of the output of said first amplifier circuit means to said second amplifier circuit means for supplying a carrier signal to said second amplifier circuit means, i. circuit means coupling said scan antenna to said second amplifier circuit means for amplifier modulating the carrier signal of said second amplifier circuit means whereby the command signals transmitted to said missile modified in accordance with target position information transmitted from said missile.
 2. In a system for guiding a missile to a distant target the combination comprising: a. means located at the missile launching station for transmitting command guidance signals to said missile and for illuminating the target with a radar beam, b. receiving antenna means located on the rear portion of said missile for receiving said command guidance signals directly from said missile launching station, c. scan antenna means located on the forward portion of said missile for receiving echos of said radar beam from said target, d. a first traveling wave tube amplifier having an input coupled to said receiving antenna means for amplifying said command signals and having an output, e. detector and decoder means having an input coupled to the output of said traveling wave tube amplifier for supplying command signals to the flight control system of said missile, f. transmitting antenna means located on the rear of said missile for transmitting a signal to said launching station, g. second traveling wave tube amplifier means having an output coupled to said transmitting antenna, h. circuit means coupling a portion of the output of said first traveling wave tube to said second traveling wave tube for supplying a carrier signal to said second traveling wave tube, i. circuit means coupling said scan antennas to said second traveling wave tube for amplitude modulating the output of said second traveling wave tube whereby the command signals transmitted to said missile may be modified in accordance with target position information transmitted from said missile. 